What’s your vote for the most ridiculous, overpriced, and useless tweak?

Any wire that is larger in diameter than what you already have inside the wall.
e.g. going from 14 gauge Romex to a 10 gauge single core power cord makes zero sense.

Love cables elevators and power cords great way to spend that extra cash.

Statue of Liberty souvenirs from NYC make excellent cable lifters. 🔝

Audio magazines.  
There are articles I feel the expert writer is concerned with the word count over the content.  Many times has the article had the "I, Me, Mine" focus then wrote about the subject of review.  Unless the information pertains directly with the subject, the writers cuteness and personal life expirences can be omitted.  I have subscribed to many of the magazines since the 70's.  Todays publishers have a difficult time.  

Tweeks come and go.  Some work and others work well for the persons on the other side.  

What about Kemp Electronics Tachyon box of BS. Tachyons don't even exist, and certainly no one is creating them for a hi-fi tweak. If they just said it was a magical box I wouldn't be getting on their case, but to throw out some absurd scientific BS just to get gullible hobbyists to give them money is disgraceful.